4 Truths about the 4 Month Sleep Regression

4 Truths about the 4 Month Sleep Regression


By Brittney Stefanic

If you Google “4 month sleep regression” you will find 27 million results. Yes, million. Holy heck. Why so many? Well… Because it is something that all families go through and a lack of sleep can have a lasting impact on these parents and little ones, alike.


You likely don’t have time to sift through all those articles, blogs, videos and opinions, after all, you are scrolling as you hold your sleeping baby, hoping that they don’t wake up the second you set your phone down. So, for you, we will keep this brief.


If you are looking for the basics behind the four month sleep regression, you have found them! Scroll on for four truths that will help you out of this sleep struggle as early as tonight. 


Truth 1: The sleep changes at 4 months are a progression not a regression

As a sleep expert, I am asked many questions about 4 to 6 month olds and their lack of daytime and nighttime sleep. This isn’t all that surprising because of the biological sleep changes that little ones go through around the four month mark. 


This sleep regression is actually a progression and is the the result of babies sleep cycles being re-organized from a two part newborn sleep cycle to a four part adult cycle. That’s right, your little one now has the sleep cycles that they will have for the rest of their life… Four glorious stages repeated multiple times a night. 


The great news here is that by taking this chance to teach the skills they need to string those sleep cycles together, you will be giving them a gift to enjoy the rest of their life… The gift of sleep! 


Truth 2: More sleep means less props

We learned above that sleep biologically changes around the four month mark and there is another major contributor that often results in the sleep fiasco that happens with four month olds. Up until this point, most parents have either been putting their baby to sleep with a pacifier, rocking, breastfeeding, or some similar technique where baby is assisted along the road to falling asleep by using a sleep prop. 


Once baby reconfigures sleep to match the four stage adult sleep cycle, they are spending more time in light sleep, and therefore there is a higher probability of waking up. The sleep props, or sleep associations, that are used can be very sneaky because although they may be helpful in getting your little one to that initial nodding off stage (what we call “sleep onset”, they may become dependent on needing the props to fall back to sleep after waking in the night. 


When baby wakes between sleep cycles and doesn’t have the paci, rocking chair or feed to initiate sleep again, you can go ahead and assume that they will be looking for that assistance to get back to sleep. When this starts happening every 45 minutes to one hour, parents are quick to find themselves in a nightmarish situation with lots of anxiety and not much sleep. 


Truth 3: Independence is Key

You will likely find that the things that worked to get your newborn down to sleep are a lot less effective once this change takes place at four months which is why it feels like the biggest regression EVER! The basic premise of the sleep changes that happens around the four month mark is that until your baby learns how to fall asleep independently, it is going to feel like you have taken a big step backwards in the sleep department.


Until a little one learns how to fall asleep on their own (prop free as described in truth 2 above), they will be constantly searching for their prop again.  


When parents hear about sleep independence, they often are curious about crying. I’ve been doing this long enough to know that change is hard! Since babies can’t communicate by telling you that they are thrown off by the behavioral differences or habit alterations, most of them cry (a least a little bit) when we modify their routines and practices. 


BUT this does not mean that you have to leave baby alone in a room to cry for hours on end. There are tons of “sleep teaching” methods out there, so do a little research and find one that feels like the best fit for your family as you navigate the four month sleep regression.


Truth 4: Sleep Environment Matters

One of the culprits of crummy daytime and night time sleep is an environment (nursery or bedroom) that hasn’t been maximized for sleep. 


To start, add a white noise machine into baby’s sleep space to block out external noise. Whether it’s the package delivery man, your loud dog warning you that the neighbor is walking by or something falling on the floor three rooms away because big brother loves to throw things, unexpected noises like this can startle a baby awake no matter where they are at in their sleep cycle. This is especially true now that she is spending more time in lighter sleep since the four month regression hit.


Next, make sure the nursery is DARK.  Blocking out all of that light out of baby’s room is important in cueing to their body that is it time for sleep. Please note that having blackout shades is not always enough as there is often “leaking light” around the sides, top and bottom of curtains and shades. Infants are very responsive to light which signal their brain it’s time for activity and alertness causing the brain to secretes hormones accordingly. 


A sleep space that is quiet and dark is the best way to increase the likelihood that your baby will successfully connect their sleep cycles independently for nice, long naps and restful nights.





Brittney Stefanic is a whole-family certified sleep consultant and founder of Sleeper Teachers®. She is an advocate for sleep education and believes in the power of rest so that families can live their best lives full of health and happiness. Brittney and her team love educating and support families around the world in finding sleep solutions through their customized sleep plans. You can follow the Sleeper Teachers® on Instagram, Pinterest, and Facebook @sleeperteachers for funny Reels, lots of blogs and frequent sleep Q&A sessions.





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